Just had my right exhaust manifold replaced on my 2015 Ram 2500 5.7 4x4. It was the third time the studs broke and the manifold warped. I have lifetime powertrain warranty but each time cost me $200 deductible. I told them this time I was not paying it to they checked the manifold and it was warped bad. They said because the studs kept breaking it cause the manifold to warp. They replaced the studs and the manifold and so far 2500 miles and no further issues, but I will be watching and listening...